What amount would need to be deposited today at 12% and compounded quarterly for 15 years that would yield the same final amount as deposits of $3000

at the end of each6-month period for 15 years at 4% but compoundedsemiannually? Which of the financial formulae are appropriate and what would be that lump sum needed? I'm really guessing at the set up based on some similar questions in my Teachers Textbook.